How much silver solder do I need?

I'm soldering a two 1/2" hex fittings and two 1" fittings into my ss kettle and I was wondering how much solder and flux I would need? Just ballpark

I picked up a Sta-Brite kit from my local welding supply shop for about $11.00 that contained enough silver solder for 6-8 1" fittings. If you dimple the kettle and form a ring of solder around the fitting you should be fine. When I did one I used only the circumference of the fitting worth of solder.

+1 to ChuckO I used the same stay-brite (Radnor branded for AirGas) kit and was able to do my test soldering of 3 washers onto the cutout lid of a sankey, and 2 1" locknuts. I probably used too much solder on the locknuts and I had to re-do one of the washers. So, YMMV, but one kit should be enough for what you need.

http://www.airgas.com/browse/productDetail.aspx?Category=26&product=RAD64001776

bbognerks, What was your process for soldering the locknuts? I've read that after you clean and flux just put a ring of solder around your hole and then set the locknut on top of the solder. Then, heat the nut till it sinks into the solder as it melts. Seems pretty foolproof.

Yeah that probably would have been better, though not how I did it. First I roughed up the keg and the face of the locknut I was going to solder. Then I just put a ring of flux around the hole and placed the locknut on the keg. I then put down some more flux by dripping it down the sides of the locknut and heated the locknut. Then I basically poked the solder into the seam where the locknut met the keg and soldered it that way. As long as it's hot enough and the keg is level, the nut doesn't move. I used a lot to make sure it got all the way under and made a good seal.




Edit: If you are going to go with the ring of solder method, make sure you flux the face of the locknut. Flux must touch what you want to solder or it won't make a good bond.

I've soldered a good amount of copper so I have a leg up on some people. My main concern is getting the solder by the edge of the hole without getting any in the thread.